Question

A hydrometer submerges to mark $X$ in water. In turpentine, it will submerge to a mark

• A. below $X$.
• B. above $X$.
• C. $X$.
• D. zero.

Answer 1

The correct option is B above $X$.

Answer is B.
The operation of the hydrometer is based on the Archimedes principle that a solid suspended in a fluid will be buoyed up by a force equal to the weight of the fluid displaced. Thus, the lower the density of the substance, the further the hydrometer will sink.
Hence, the hydrometer submerges to mark X in water and in turpentine, it will submerge above the mark X.